Week 7 Flashcards
What is the purpose of an IP address?
To allow communication between devices over a network by acting as a unique identifier for each device and facilitates the transport of packets from source to destination by DEFINING the communication pathway.
What is the size of source and destination fields of IPv4?
32 bits EACH
How many combinations of IPv4 are possible?
2^32
What is the size of the source address and destination address of IPv6 addresses?
128 bits each
How many classes of IPv4 addresses are there?
5 classes
A, B, C, D, E
NOTE: D and E unaccessible for public
How to determine dotted decimal notation of binary representation of IP address with address
11001010000010010101111110111100
11001010.00001001.01011111.10111100
11001010 = 2^7 + 2^6 + 2^3 + 2^1 = 202 00001001 = 2^0 + 2^3 = 9 01011111 = 2^0 + 2^1 + 2^2 + 2^3 + 2^4 + 2^5 = 95 10111100 = 2^2 + 2^3 + 2^4 + 2^5 + 2^7 = 188
202.9.95.188
How to determine dotted decimal notation of binary representation of IP address with address
11001010000010010101111110111100
11001010.00001001.01011111.10111100
11001010 = 2^7 + 2^6 + 2^3 + 2^1 = 202 00001001 = 2^0 + 2^3 = 9 01011111 = 2^0 + 2^1 + 2^2 + 2^3 + 2^4 + 2^5 = 95 10111100 = 2^2 + 2^3 + 2^4 + 2^5 + 2^7 = 188
202.9.95.188
What is classful addressing?
Different configurations of 32-bit IPv4 addresses that are classified into either A, B, C, D or E class addresses
Can classful addresses be directly implemented in one location?
No, these must be divided into smaller addresses aka SUBNETTING
What is subnetting?
Dividing classful addresses into classless addresses
This creates subnets
What is classless addressing?
These are when classful addresses have been subnetted into subnets.
Subnets are classless
How to subnet a classful address into classless?
- Convert decimal into binary form
- Remove x bits from the host ID. Bits taken from MSB
- Removed bits are subnet ID bits
- x^2 bits is the number of subnet masks generated
Why classless used over classful?
Not practical to deploy classful, too many IP addresses for only one location. Subnetting allows more efficient use of network as subnetted network can be split between locations.
How are network and host part of an IP address idenfitified in classless addressing?
There must be a subnet mask to define the network and host part of the address
Stolen bits from host ID become subnet bits
For each of the following Classless IPv4 addresses and their corresponding subnet
masks, find out the network address, the subnet’s broadcast address, and the
number of usable addresses in that subnet.
a) IP address: 192.168.13.23, subnetmask: 255.255.0.0
OPTIONA:L
b) IP address: 130.194.77.37 subnetmask: 0xfffffe00
c) IP address 130.194.66.77 subnetmask: /26
a) IP address: 192.168.13.23, netmask: 255.255.0.0
192.168.13.23 = 11000000.10101000.00001101.00010111 (convert decimal to binary form)
255.255.0.0 = 11111111.11111111.00000000.00000000 (convert decimal to binary)
0.0.255.255 = 000000000.00000000.11111111.11111111 (determine wild card, reverse of subnet mask)
Get network (perform AND operation between address and netmask)
Get broadcast address (perfom OR operation for 1 bit between address and wildcard)
Host min address is Network + 1
Host max address is Broadcast - 1
Range = broadcast - network - hostmin (1) - hostmax (1)
OPTIONAL:
b) IP address: 130.194.77.37 netmask: 0xfffffe00
c) IP address 130.194.66.77 netmask: /26
